In order to fix the problem, I recommend you update the program to the latest version. After that, launch the software and from the Tools menu select Background image > Manage background images. Click the arrow icon next to + and then select SHP or DXF from the provided list:

Using the window that will open, select the image for your background and press Open. If you still have problems, I recommend you contact the support team using info@transparent-blue.com
email address.